We agree that our measurement of distance is a human construct, created to allow us some judgement of space.
We agree that the concept of 'time' is also a human construct, created to allow us some measurement of the rhythm of life.
We must also realize that the concepts of 'beginning' and 'ending' are no different - human constructs of language which allow us to quantify and measure these common phenomena in our world; the illusion of things starting stopping.
This language is a simple tool of measurement, is shallow, and should not be mistaken for the EVENT which we try to measure.
Look at even the simplest thing, a human birth. Where does that event begin exactly? When the child is birthed from it's mother? When it is a fetus in the womb? As a sperm fighting to reach the egg - is it not still beginning? And before that as two people bouncing around this world, still yet to meet.. is it not also beginning at that point?
Death is the same... has your life ended when your body no longer functions? Don't the actions of your life still resonate through the world through the people who knew you or the influences you had? This life is still traveling and living in some form. As you decompose and your minerals are absorbed by the earth, has your life ended, or is it still traveling through the plant life that its nutrients spawn?
My point is, with questions like these, you end up trapped, arguing about the flaws of the measuring tool - in this case, language. Language is a clunky, flawed system with which we (the experience itself, I may add....we are both the observer and the observed) attempt to translate and communicate our experience. You can no more succeed at that than you can bite your own teeth, or touch the tip of your right hand index finger, with the tip of your right hand index finger.
For those of you who like metaphysics, philosophy, relegion and discussions of this matter, I seriously urge you to look for some books, audio recordings, and video of the late, great Alan Watts. He is my favorite philosopher, and a great character from the 60's, 70's. (10 points to anyone who can find my alan watts quotes).
Here's a good video of his to start with.
part 1
http://www.youtube.com/watch?v=8aufuwMiKmE
part 2
http://www.youtube.com/watch?v=dZ8WeLrtFnY